1. Field of the Invention
The present invention relates to an injection mold for a light guide body that disperses light transmitted from one optical fiber and transmits the light to a plurality of optical fibers, and an apparatus for manufacturing a light guide body using the same.
2. Description of the Related Art
For example, an optical sheet bus for dispersing light transmitted from one optical fiber and then transmitting the light thus transmitted to a plurality of optical fibers has been recently developed as a bus for optical communications. A sheet achieved by shaping material of polymethyl methacrylate (PMMA) or the like in the form of a rectangular sheet has been known as an optical sheet bus as described above (see JP 11-31035 A).
Since the conventional optical sheet bus as described above is designed in a rectangular shape, there is a risk that light is not efficiently transmitted. Specifically, in a case where three optical fibers 120 are connected to one end face 110a of an optical sheet bus 110 as an input side and one optical fiber 120 is connected to the other end face 110b as an output side as shown in FIG. 16A, when light input from one optical fiber at the one end face 110a side travels to the other end face 110b while diffusing in the optical sheet bus 110, a part of the light enters the optical fiber 120 at the other end face 110b side, however, the other part of the light is reflected at a wall of the other end face 110b side (see the shaded area in FIG. 16B as viewed from the arrow Z of FIG. 16A) and returned to the one end face 110a. Accordingly, the light cannot be efficiently transmitted.
Furthermore, when light is transmitted from the optical fiber 120 at the other end face 110b side to the optical fiber 120 at the one end face 110a side as shown in FIG. 16C, a part of the light is likewise reflected at a wall of the one end face 110a. 
The optical sheet bus as described above is used while connected to a plurality of optical fibers. In this case, the optical fibers are extremely narrow fibers and thus a method of efficiently performing the connection between the optical sheet bus and the optical fibers has been demanded.
Therefore, it would be desirable to manufacture a light guide body to efficiently perform the connection of optical fibers to an optical sheet bus.
Illustrative, non-limiting embodiments of the present invention overcome the above disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an illustrative, non-limiting embodiment of the present invention may not overcome any of the problems described above.